GRAYLING SPAWNING REPORT 



southwest Montana (Nelson 1954); fran early Jane through late? 

 June in an inlet stream to Lake Agnes in southwest Montana 

 (Peterman 1972); and fron iriid-JLily thrDugh late July in an inlet 

 to Hyalite Reservoir, near Eoz^man, Montana (Wells 1976). A 

 revie'Aj of grayling studies conducted in Alaska found the majority 

 of those grayling populations spawried from mid-May to mid-June, 

 however, some populations were found to spawn as early as lata 

 April and others as late as early July (Armstrong 1986). A 

 review of studies conducted in Canada found that spawning 

 generally occurred from April through June ( Rawson 1950; Bishop 

 1971; McCart et al . 1972; de Sruyn and McCart 1974; Tripp and 

 McCart 1974; Kratt and Smith 1977? Talk et al. 1982). 



In past studies of grayling m Montana spawning was found to 

 commence when water temperatures reaKzt-\^d the 40—50 F range and 

 the upper end of this range was the suggested temperature where 

 most spawning activity was observed by the majority of the 

 authors (Brown 1938; Tryon 1947; Nelson 1954; Kruse 1959; Hoi ton 

 1971; Peterman 1972; Lund 1974; Wells 1976). Lund (1974) also 

 documented that grayling began their spawning runs on declining 

 stream flows in inlets to Elk Lake, Montana when daily stream and 

 lake temperatures averaged approximately 45 F. Water temperature 

 and spring flooding were believed to be factors that stimulated 

 spawning in Armstrong's (1986) review of the Alaska studies on 

 grayl.mg. Specifically, Tack (1973) believed that a water 

 temperature of around 39 F triggered grayling spawning in 

 interior streams of Alaska which was also the temperature Alt 

 (1976) suggested grayling spawned in wastern Alaska. Warner 

 (1955) also found grayling spawning at around 39 F in some inlets 

 to Fielding Lake, Alaska. Bishop (1971) noted that grayling 

 moved onto spawning grounds at water temperatures of 46 to 50 F 

 and that spawning took place ^t 50 F. Canadian studies have 

 reported water temperatures between 39 to 50 F to be an important 

 cue for the initiaTiion of grayling spawning (Rawson 1950; Fripp 

 and McCart 1974; Stuart and Chislett 1979). 



CHARACTERISTICS OF THE SPAWNING RUN 



The sex ratio for the Big Hole grayling spawning population 

 was 2.0 males: 1.0 female. Kruse (1959) documented sex ratios of 

 spawning runs into Grebe Lake, Yellowstone Park, spawning grounds 

 to be 2.0:1.0 in 1953 and 0.9:1.0 in 1954. Lund (1974) found 

 that females outnumbered mal'-;s in spawning populations of 

 grayling entering Narrows Creek fr^m Elk Lake, Montana at a rar.io 

 of 2.1:1.0 and 1 . 7 : 1 . (/ m J 972 end 1973, respectively. Bishop 

 (1971) found a sex ratio or spawning crayling entering Providence 

 Creek, a tributary to Great Slave Lake in Canada to be 1.3 

 males: i.O female. Ward (1951) found the sex ratio changed during 



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